Preparation of charge



July-f'l13r1939-I K. A.G.KEE TERK|KN 'I PREPARATION or `Grimm Filed Feb. T21, 1'336l sa miie? i wrhundlrm 525.

` INVENTOR- l, *ALBERTGPETERKIN V." u ,Y

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5 ATTORNEY Patented July is, 193.9 i A l2,166,176

2,166,176 PREPARATION F CHARGE Albert'G. Peterkin, Bryn Mawr, Pa., assigner to= Houdry Process Corporation, Dover,` Del.,y a -y `corporation'of Delaware l f i.

v UNITED'STATES yraffle-N15 ori-ica Application February 21, 1,3316, Serallm 65,013 u s Claims. (ci. 19e-,52)

The present invention relatesy to .the art of boiling material. A further object involves a t treatingy composite materials, especially v fluids two-stage separation ofundesirable, heavy cornhaving a wide boiling range andcontaining components from a vapor liquid stream directed toponent's which may be undesirable f orcertainr wardy a reaction chamber or converter.

operations. It has particular reference` to oper- Furtherobjects and advantages as 'well as a 5 s ationswhere it is desired to have the materialv quick understanding vof the inventioncankbest be to be treated completely in the vaporphase.l Il obtained byreference to the accompanying drawlustrative ofthe composite materials which it is ingirrthe'single iigurer of which: f contemplated to treat are hydrocarbons, includl represents'atar separator or equivalent flash 0 ingvthose of petroleum,` coal, shale or other orichamber fractionator vor the like,-"2 represents a r10 gin, natur-a1 or articial.y Iny this `class oiV4 matar separator or partialcondenser;l 3represents i terials are crude petroleum foils, k,topped crudes a tar separator or partial condenser,y 41 repreand also bottoms or residual fractions thereof. sentsa'fractionating column or equivalent, 5 rep- When these materials are charged .directly to a resentsa converter, which by way of illustration .l

5 reaction chamber such as a cracking stillfor other may be Aconsidered to be a converter containing i5 conversion or transformation ch-ambenfor exa contact mass or catalyst, and 6 is a viscosity i ample, to a converter containing a ,contact mass breaker oran apparatus in which amild cracking or catalyst, considerable difficulty is often encan'be effected. While 6 is illustrated as a thercountered because of the presence of vundesir- `mal viscosity breaker, it may be any other ytype able material, usually in small amount, which of viscosity breaker, such as a chamber containing tends to promote condensation and to cause ,cokan inert or relativelyl inert :contact mass, such,

l ing or obstruction of theapparatus. To minimize for example, as disclosed in United States Patent this difficulty, largeamounts of steameor other YNo.r 1,818,403,` issuedA August 11', 1931 to Alfred fluidfhave been used in some` instances' as an Joseph. f ,f aid to vaporization, involving a considerable exj- Thelinvention is illustrated by considering a 25 pense. .Other expedients have beenv to employ crudev oil as the material from which a chargingvv temperatures `of'reaction -above the optimum or stock for a converter is to be prepared. Crude to effect acostly or wasteful fractionation ofthe oil may beforced by pump 1 through heat'exf charg y u ,t "changer 8 and thence through line Sand heater A purpose of this invention-ls ,te-prepare a 'lo (or partly or whony through line Il eon- 30 clean, vaporous charging stock for a transformatrolledv by va1ve Hw) into fractionating columnl I. tion or conversion,for example for .acatalytic Low boiling hydrocarbons, consisting of 10W boi1 tra fOrrning Operation, from e Composite maing gases, gasoline and preferably also kerosene teria such as from the hydrocarbon materiels or light kerosene fractions, are withdrawn from abovev indicated, andi@ d0 this efficiently and the top ofthefyractionator; Amiddle cut, which 35 eeonomieally- AnOthel Object `is te free o the is preferably adeep cut including everything'from Charge Of all the undesirable heavy and high bOilthe, kerosene range to the heaviest f components ing components presentI Another Object iS t0 of the crude which can be vaporized without a minimize the amount `0f yStettin 0r Other fluid substantial amount of thermal cracking, is withneeded t0 free the/Charge Of undesirable Coindrawn vfrom an intermediate point rofthe frac- 40 ponents and to rpresent yit in proper vener phase tionating column and may beforeed by pump l2 COnditiOnrfOI e0nVeI`Si0n, e, g, in Clean, dly through the lines shown leading to heating or saturated or preferably superheated state. Ansuperheating coils' I3, which may comprlsethe ra- Other Object -inVOlVes the treatment 0I' Processing diation bank of coilswithin a heater or furnacev of composite material such. as crude oil or topped M Y From themsuperheating coils I3, vapors may 45 Crude 01' distillation bOttOms, byv eliminatien 0f pass through the line shown to converter 5. From v the highest boiling deleteriOuS; COInponents with the converter` Sreaction products leayethrough a minimum sacrifice of desirable vaporiaable m'aa line I5 and, en route to storage tanks or other teri-als. Stillanother object includes Separating receptacles or apparatus,l arer cooled in passage Y out'portions ofa crude oil which do notrfavorthrough heat exchanger B.

ably lend `themselves to direct conversion vintok The bottoms cut or fraction from the fractionvaluable products, subjecting such portions to ar ating column vIr',fcomprising rhigh boiling rcommild conversion or viscosity breaking operation ponents of the crude having a gravity of, for exand then separating'the lighter portions of the ample, `5" to 20 A;P.I., is withdrawn through the resultant product from the remaining heavy high line shown and forced by'pump I6 through coils 55 I'I, which may comprise the convection bank of coils of furnace Il, into tar separator 7|. The hydrocarbon material entering tar separator I will be at a temperature of the order of 850 to 1000 F., with a preferential range of'about 875 to 950 F., 925 F. being a good temperature in the case of a number of crude oils, e. g., East Texas crude oil. A vaporizing uid such as steam, in quantities of the order of 1 or 2% to 20% or so by weight of the bottoms may vbe introduced with the latter through line I8, con-` trolled by valve i3d. Amounts ofthe order of 10% by weight -of the bottoms will be suitable with certain oil stocks such as the East Texas crude mentioned. In any event, the amount of vaporizing fluid is sufficiently large to control to the desired degree or eiiminiate thermal cracking in the coil Additional amounts of steam may be introduced into admixture'with the hydrocarbons in separator I through branch I9, controlled by valve Isa. The steam introduced through branch I9 may be in small amounts up to 5% or sometimes 10% of the charge'to the separator, the amount of steam preferred being that which will control the character of the heavy tar or liquid withdrawn from separator I through line 20 to the consistency desired. It is preferable that no readily useful materials for conversion,

i. e., materials from which gasoline or the like can be produced without the attendant production of relatively large amounts of coke and gas, be withdrawn through line 20. In short, the fluid withdrawn through line 20 is usually controlled by regulating the proportion of steam added to the charge to separator I so that-it is of a very heavy tarry nature, having a gravity of the order of 5 to 15 A. P. I., as for example, 10 A. P. I., and is not capable of being used to vadvantage in further processing for the production of motor fuel but can find use as a starting material in the production of asphalts or the like or as a heavy fuel. However, liquid withdrawn from separator I may be forced by the pump shown into the line leading to viscosity breaker 6. If this option is followed, normally a somewhat lighter material, e. g., one having a gravity of 8 to 20 A. P. I., may be withdrawn from separator I through line 20.

Vaporous materials are withdrawn from separator I through the line 2| and pass into separator 2, where the components of the charge which are too high boiling to be held in the form of vapors for conversion at the temperature and pressure desired in the converter 5 are condensed and separated out. The desired temperature in the case of catalytic conversion, for example, may be of the order of r" to 950 F., depending upon the particular catalyst employed and the conditions of operation.

The catalyst or contact mass may be of any known or desirable type. Suitable contact masses include, by Way of illustration, silicious materials, as for example naturally occurring or artificially prepared blends or mixtures of silica and alumina, preferably in molded or fragmentary pieces, and, where desired, having metal oxide or oxides admixed therewith. This type of Contact mass is illustrated in copending application of Eugene J. Houdry, Serial No. 35,101, led August '7, 1935. With certain charging stocks, including stocks such as East Texas crude, mentioned above, and with a contact mass, such as the types just mentioned, transformation temperatures of the order of 810 to 925 F. are often employed.

Controlled amounts of the middle cut from fractionator 4, for example amounts of the order i of 1 to 15% by weight of the overhead from separator I, may be introduced through line 32, controlled by valve 32a and pass through line 2|, with the charge, to separator 2.' The temperature of the middle cut, so introduced, may be controlled by passing any desired proportion of or the whole middle cut from column 4 through valve 22 and 'heat exchanger 23. The temperature of the middle cut may be from about 250 F. upwards to a temperature preferably not in excess of its average boiling point. Since the purpose of introducing a proportion of the middle cut is to effect a partial condensation of the vapors passed from separator I to separator 2, the temperature of the middle cut must, of course, be below its average boiling point. .The higher the temperature of the cut admitted to separator 2, the higher in general will be the amount of the middle cut required; whereas where lower ternperatures, for example, of the order of 250 to 400 F. are employed, relatively lower amounts of middle cut will be required to effect the desired partial condensation. The character of the partial condensation is controlled so that the overhead from separator 2 will consist of a clean stock which readily will remain in the vapor phase in converter 5 under the conditions of temperature and pressure desired therein, e. g., under temperatures of the order of 810 to 925 F. and pressures of the order of 1 to 5 atmospheres and so that the condensate is of such a character that it can be mildly cracked in Viscosity breaker 6 without necessitating the use of large amounts of steam and without producing large amounts of coke and gas.

The bottoms from separator 2 are forced by pump 24 through heating coil or viscosity breaker 6 to effect a mild cracking operation and from there the residual material passes into separator 3. Small amounts of steam, for example, 1% more or less by weight of the bottoms withdrawn from separator 2, m-ay be introduced into the viscosity breaker through line 25, controlled by valve 25a, thereby to control the viscosity breaking operation and to minimize the formation of carbon. The tar separator or fractionator 3 is operated so that heavy liquid withdrawn therefrom through line 26 will be of a high boiling refractory character making it unsuitable for conversion into motor fuel or gasoline. The particular conditions of separator 3 may be controlled by the admission of suitable amounts of steam or the like, e. g., l, 2 or 5% thereof, through line 21, controlled by valve 21a. The gravity of the heavy liquid leaving separator 3 through line 26 may be of the order of 5 to 12 A. P. I.

When the vapors and steam or equivalent leaving separator 3 are of sufficiently high temperature, they may be passed directly through line 28, controlled by valve 28a to the converter 5 with the possible addition of further small amounts of steam, if desired, through line 29, controlled by valve 29a. But if such vapors are not of a sufficiently high temperature to be passed directly to theconverter 5, they may be passed through line 30, controlled by valve 30a and be admixed with the middle cut in line 3|, preceding the superheating coils I3.

Then the mixture of the middle cut together with vapors entering line 3| from separator 2 and those entering line 3| from separator 3 may be passed together through the heater I3 to the 2,106,176 converter 5. The temperature of the reactants in. the line leading tothe converter is usually fromv 10 to 40 or 50 F. higher than the temperature how strongly ,endothermic is the `transformation or conversion. Howeverjwhen :there is provision for heat input in the reaction chamber. orl within the catalytic mass, las for examplein certain' copendingapplications including that ,of E'. J.

Houdry et al. Serial No.l28,544'flled June 1, 1934, the reactants maybe charged at or VevenA below the desired reaction temperature.

It will benotedlfthat all or. practicallyall of l the materials suitableffor conversion aresepa-v rated yfrom the undesirable orH very heavy high;

`boiling carbonaceoustarry and asphaltic corn-y ponentsof the crude oil orfcomposite charge inv l an eflicient manner and with the use of a rhini-` mum of steam or equivalent vapOrizingJfiuid, Also, :itwill be seen that other components of the composite material, whichy are suitable',"after.

additional treatment, for charging tor a converter, are separated out', Ysubjected to a 'viscosity breaking operation and the resultant' desirable products are addedtto the vapor phase. stream sent to converter 5. It will be seen that the steam,

or equivalent, used to, cont/1701 the viscosity brakllng reaction and that employed to assist invaporization and separation of desirable `components from the high boiling, undesirable components, is further utilized, e. g. inv a specialmanner o f the type illustrated,` in rsubsequent heating or superheating and/or conversion for desired purposes, for examplev to keep down thermal cracking in the heating sktepand to serve as a desired auxiliary fluid in the conversionstep. words, the invention makesan effective removal o-f tar and asphalt so as to present a substantially clean chargein vapor phase having the desired content of steam (or other gaseous material) for the transforming reaction ,with anVeconomical use ofthe same.`

, while the invention is k11'1ustri-,mefi inepn'nect-ionwith entire crudes, it will bereadilyV appar- 'entthat it is equally applicabletotheftreatment ofatopped crude o r a crude ,fromwhich the light fractions suchas gasoline have alreadybeen removed, for,` as is apparent, ithe low `boiling hydrocarbons such as gasoline play no essential partin the major aspects kof this 'invention'. Also, the invention,or rather ha majoraspect thereof, is illustrated `by employing as charge abottoms or residual fraction from a cru`de,rathe'r than theentire or a topped or crude oil'. For this material column 4 would notkbe required; instead, the bottoms fraction would vbe .pumped directly Yto'heater- I1-, and its progress is then 'essentially the same las in the particular illustrative embodiment described above. Where material of the nature of the middle cut is desired to control partial condensation Ain separatori, which is not necessarily required'in the broadest aspect ofmy inventiornthe same may be supplied from a separate source. The required amounts of such material are small, as of the order above specified,

f as for example, 2 to 5% of' the vapors `passing from separator i toseparator 2 .Where the temperature of such lower `boiling fraction .is kept substantially below its average boiling point.

The present invention, while having some very In other y general relationfto that involved inmyA copending application, Serialk No. 65,955, filed 'February 2'1,y 1936, ydistinguishes therefrom.` In particular, in the present, invention the composite' fluid charge is'separated into a bottoms fraction and one or'more lighter `fractions including an inter- `rmediate fraction, the bottoms fraction is vapor-f ized without any substantial cracking ror con.

,version withtheaid'of'afvaporizing iluid and the vapors soproduced may be mingled* with' the intermediate fraction and passed 4to ya conversion zone under conditions Adesired for vapor phase conversion; Whereas inmy aforesaid 'copending vapplication any .bottoms separated from the chargerto the process are subjected to a conver-` sionor4 viscosity 'breaking before beingrecom` bined with any other vapors passingto a cracking.

zone.

{WhatIclairn is'; 1. In an operation for attaining a highyield of vdesired low boiling hydrocarbons within the light ist motor fuel or gasoline boiling range from a comvpositer hydrocarbon starting material of wide boiling range, containing components which are too high' boiling and ofl too high'fmolecular weights to be capable of being vaporized by heat alone without substantial thermal cracking thereof` along with lower boiling Yhydrocarbons including'readilyy vaporizable materials higher boiling than the'desiredilow boiling motor "fuel product or gasoline,` thev steps'of process which include [dividing said composite material into a 'bottoms orjresidu'al fraction, containing diilicultly toms fraction into lower boilingA hydrocarbons,

continuously passing said heatingy stream inw -a separating zone and therein separating unvaporized liquids from vapors, withdrawing `rliquids from said separatingl zone" as one stream and withdrawing vapors, 'including hydrocarbon vaporsand vaporizing fluid, therefrom as a second l stream," combiningA said second stream with the aforesaid ',distillatefraction at' desiredtemperai ture,ithereafter raising the temperature of the resulting combined stream of' vapors sufilcientlyy so that it will approximate the ytemperature de-V sired for the subsequentgconversion stepy and willv be in' va ,statel of superheat, then `passing said stream of vapors intova conflnedreaction zone Vcontaining solid, adsorptive lsilicious catalytic material and `being maintained under conditions soos to effect a' cracking or transformation of hydrocarbons-charged thereto to a. large extent into desired 'lowboiling hydrocarbons orgasoline,

and withdrawing a stream of products of reaction 'from said confined reaction zones; y

, 2j Inan operation for attaining a high yield of desired low boiling hydrocarbons within the light motor fuel or gasoline boiling range from a comyposite hydrocarbon starting material of Widev boiling range, containing components which are too high boiling and of too high molecular weights to be capable of V,being vaporized by heat alone without substantial thermal cracking thereof along with lowerboiling hydrocarbons including readily vaporizable materials higher boiling than the desired low boiling motor fuel product or gasoline, the steps of process which include dividing said composite material into a bottoms or residual fraction and at least one distillate fraction consisting primarily of components above the said light motor fuel or gasoline boiling range, heating a continuous stream of said bottoms fraction with the aid of a vaporizing fluid so as to vaporize the same to substantial extent Without causing substantial conversion of components of said bottoms fraction intol lower boiling hydrocarbons, continuously passing said heated stream into a separating zone and therein separating unvaporized liquids from vapors, withdrawing liquids from said separating zone as one stream and withdrawing vapors, including hydrocarbon vapors and vaporizing fluid, therefrom as a second stream, addingadditional vaporizing fluid to said vapors, combining the resulting stream of vapors with a stream of the aforesaid distillate fraction at desired temperature, passing the resulting combined stream through a heating zone wherein said combined stream is brought up to a temperature approximating that desired for the subsequent conversion and the vapors are superheated while avoiding any substantial conversion thereof into lower boiling hydrocarbons, then passing said stream of vapors into a confined reaction zone containing solid adsorptive incombustible catalytic material and being maintained under conditions so as to effect a cracking or transformation of hydrocarbons charged thereto to a large extent into desired low boiling hydrocarbons or gasoline, and withdrawing a stream of products of reaction from said confined reaction zone.

3. In the preparation of a hydrocarbon charge for a conversion operation from a composite material having a substantial boiling range and containing components which are undesirable because of their heavy, high-boiling character, the steps of process which comprise dividing said composite material into a bottoms fraction and at least one distillate fraction, vaporizing a substantial portion of said bottoms fraction with the aid of heat and a vaporizing fluid and without effecting substantial conversion of said fraction into gasoline, passing such fraction together with vaporizing fluid into a separating zone to separate unvaporized liquid from vapors, withdrawing unvaporized heavy material from said zone and passing a stream of the resultant vapors, and the vaporizing fluid admixed therewith, from said separating zone to a second separating zone or partial condensing zone, introducing into said second zone a portion of said distillate fraction so as to effect a controlled partial condensation of the vapors in said second zone, passing a stream of vapors from said second zone to a conversion zone, withdrawing condensed fluid material from said second zone and subjecting it to a mild cracking operation to effect a viscosity breaking thereof without producing large amounts of gasoline, passing the viscosity broken material to a third separating zone, therein dividing said viscosity broken material into a liquid fraction and a vapor fraction, withdrawing said liquid fraction from said third zone, and passing said vapor fraction from said third zone, together with the aforesaid vapors from said second zone, into the aforesaid conversion zone, the latter containing solid adsorptive incombustible contact material and being maintained under conditions so as to effect a cracking or transformation of hydrocarbons charged thereto into lower boiling hydrocarbons.

4. In an operation for attaining a` high yield of desired low boiling hydrocarbons-within the light motor fuel or gasoline boiling range from a composite hydrocarbon starting material of wide boiling range, containing components which are'too high boiling and of too high molecular weights to be capable of being vaporized by heat alone without substantial thermal cracking thereof along with lower boiling hydrocarbons including readily vaporizabie materials higher boiling .than the desired low boiling motor fuel or gasoline, the steps of process which include dividing said composite material into a bottoms or residual fraction and at least one distillate fraction consisting primarily of components above the said light motor fuel or gasoline boiling range, heating a continuous stream of said bottoms fraction with the aid of a vaporizing fluid so as to vaporize the same to a large extent without causing substantial conversion of components of said bottoms fraction into lower boiling hydrocarbons, continuously passing said heated stream into a separating zone and therein separating unvaporized liquids from vapors, withdrawing liquids from said separating zone as one stream and withdrawing vapors (including hydrocarbon vapors and vaporizing fluid) therefrom as a second stream, combining the last-mentioned or second stream with at least a substantial proportion of the aforesaid distillate fraction, the latter being at a temperature below its average boiling point when admixed with said vapors so as to effect a partial condensation of the latter, continuously separating a stream of condensed liquid from remaining vapors in a second separating zone or condensing zone, passing said remaining vapors as a continuous stream from said second separating zone through a heating zone so as to superheat the same without substantial cracking or conversion thereof into lower boiling hydrocarbons, subjecting said stream of condensed liquid to a mild cracking operation to effect a viscosity breaking thereof without causing any substantial production of gasoline, combining that portion of the products of said viscosity breaking operation having a boiling range similar to the vapors from said second separating zone with the latter at desired temperature, and passing the last-mentioned combined stream into a confined reaction zone containing solid adsorptive incombustible catalytic material and being maintained under conditions so as to effect a cracking or transformation of hydrocarbons charged thereto to a large extent into desired low boiling hydrocarbons or-,gasolina and withdrawing a stream of products of reaction from said confined reaction zone.

5. In the preparation of a substantially uncracked hydrocarbon charge for a conversion operation from a bottoms or residual hydrocarbon fraction, said bottoms fraction being made up of components too high boiling to be capable of being vaporized upon heating alone without substantial thermal cracking thereof, the steps of process which comprise heating and substantially vaporizing said bottoms fraction with the aid of a vaporizing fluid and without eilectng substantial conversion of said fraction into lower boiling hydrocarbons, passing said heated fraction together with said admixed vaporizing fluid into a separating zone, separating unvaporized liquids from vapors in said separating zone, Withdrawing liquids from said separating zone, passing a stream of vapors from said zone into a partial condensing zone, introducing into said partial condensing zone a stream of hydrocarbon fluid having a boiling range lowerthan that of said vapors but higher than' that of gasoline, in controlled amount and at controlled temperature below its average boiling point, to effect a lpartial condensation ofthe said lvapors;introduced thereinto from said separating zone so as yto remove higher boiling components which', if left in they' vapors,'would cause condensation and coke fformation in the cracking or reaction zone defined` below, withdrawing a stream of condensate from saidpartial condensing zone, subjecting said cony densate to a mild cracking operation to e'eet a viscosity l.breaking thereof, separating heavy,

high-boiling components as liquids `from therey maining vaporous products 0i' such viscosity breaking operation, and adjusting'the last-mem' tioned vaporous products and the stream of vapors from'said partial condensing zone to a temperature suitable for catalyticconversion thereof,

then passing vsa'id lvaporous products and said stream of vapors together through a coniinedy reaction zone containing a catalytic mass and' heavy hydrocarbon fraction containing compo-. nents too high boiling to be capable of being vaporized upon heating alone without substantial thermal cracking thereof, the process steps which comprise heating and vaporizing said bottoms fraction to substantial extent Vwith the aid of steam as a vaporizingiluid and without eiecting substantial conversion of said fraction into lower boiling hydrocarbons, passing said heated fraction together with admixed vaporizing fludinto a separating zone, separating unvaporized liquids from vapors in said separating zone, separately withdrawing' liquids and vapors from said separating zone, mixing additional steam with the vapors leaving 'said zone, passing said vapors from said zone into admixture with an additional stream of hydrocarbon fluid having a lower boiling rangey than said vapors but a substantially higher boiling range than gasoline, said hydrocarbon uid being at such temperature below its average boiling point and in such proportion as to effect a partial condensation of said vapors to remove the heaviest, highest rboiling components therefrom, passing the remaining vapors through a heating zone wh'erethey are raised a substantial boiling range and containingcom-l ponents which are undesirable because oftheir heavy, high-boiling character, which comprises,

in combination, means for heating and vaporizing a bottoms or residuall fraction -of said 'composite-material, a separating vessel connected to ,saidY heating and vaporizing means, said vessel .being provided with an overhead outlet for vapors and a bottoms draw-oli forunvaporized liq- 'ui`d, partial condensing means provided with separate outletsffcr vapors andcondensatevre- `s pe'ctively, a conduit for passing said vapors from lsaid overhead outlet to saidpartial condensing means, means including a heater`for effecting a moderate cracking r of heavy high boiling hydroi lcarbon fluids; a conduit for'passing said convdensate from theliquid outlet of said partial condensing means to ythe last-namedmeans, a tar separator yfollowing and connected to said lastnamed means, a converter containing soiidgadvsorptive catalytic material, and ducts for passing vapors from said tar separator and from the Lvapor outlet of the aforesaid partial condensing means to said converter.

8. Apparatus for preparing a hydrocarbon charge for vaporphase reaction -from compositehydrocarbon material having a substantial boil- 'ring range and containing components which are undesirable because of their heavy, high-boiling character, and for transforming the charge into lower boiling hydrocarbon products, which comprises, in combination, a fractionator for com-'- posite hydrocarbon material, a' heater precedingv and connected by a duct to said fractionator, means for forcing composite hydrocarbon material through said heater into said fractionator,

said fraotionator providing for separating, from the materialcharged to it, a bottoms fraction vcomprising high boiling components and a midf dle cut comprising components ranging from the` lowest boiling of said bottoms fraction to those having a boiling point of the order of kerosene components, means following said fractionator kand connected thereto for heating and partially vaporizing said bottoms fraction, a separator ,following and connected to said heating means to separate high boiling unvaporized hydrocarbons from vapors, said separator providing an overhead outlet for vapors and a bottom outlet for unvaporized liquid, a partial condenser, said partial condenser also providing separate outlets for vapors and condensaterespectively, a .conduit for passing vapors from the overhead outlet said separator to said partial condenser, a duct for withdrawing heavy liquid hydrocarbons from the liquid outlet of said partial condenser, a line from said vfractionator for withdrawing the aforesaid middle cut therefrom, means including a duct by lliy which a controlled amount of said middle cut can be ypassed `from saidy line to said partialconvapor outlet of said partial condenser to the reac# tion chamber of said converter..

ALBERT G. PE'I'ERKIN.

CERTIFICATE OF CORRECTION. Patent No. 2,166,176. July 18, 1959.

ALBERT G. PETERICIN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows; Page 5, first column, line 52-55, for the word "braking" read breaking; and second column, line mi, claim l, for "heating" read heated; page 5, second column, liv/ne 5C, claim' 8, aftery "outlet" insert of; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the .Patent Office.

Signed and sealed this 22nd day of August, A. D. 1959.

Leslie Frazer (Seal) Acting Oonnnissioner of Patents. 

